It's all in how you phrase it
> ...although the majority of Windows game development has moved toward DirectX, OpenGL still has advantages...
I'm not sure, "moved towards" is the right phrase. "Started out," perhaps, "historically" certainly, but game development in general (ok, its a finger in the air general impression) appears to be moving away from DirectX because Windows is no longer the only target. For many, it isn't even the main target - they are going for the mobile market instead.
Certainly in the indie market, I see lots of Linux and OSX stuff on Steam. Weirdly, sometimes Linux but no OSX and sometimes OSX but no Linux. There are some odd decisions out there. Anyway, with console being so big and lots of things being ported to multiple platforms, including mobile, *GL would seem to be the way to go. Consoles are never going to be pushing the envelope, neither is anything targeting the Mac market, so performance is rarely the limiting factor. For vendors, market reach usually trumps having a groundbreaking game. Roll on Star Citizen!